Walker 21399 Exhaust Muffler

Walker Quiet-Flow SS Muffler for Impala and Monte Carlo

Walker Quiet-Flow SS muffler Part Number 21399 is a specific-fit exhaust muffler built with stainless-steel body construction for a direct replacement on select Chevrolet applications. It is shaped as an oval combination muffler with a 2.25-inch inlet and 2.5-inch outlet, sized for OE-style exhaust routing and sound control.

Quiet-Flow SS Product Line

The Quiet-Flow SS line focuses on precision fit, smooth exhaust flow, and a factory-like sound profile. For drivers looking for a stainless-steel muffler replacement on a Chevrolet Impala or Chevrolet Monte Carlo, this line is built to match the original exhaust layout while maintaining a clean, serviceable installation profile.

Key Features

• Walker Quiet-Flow SS Part Number 21399
• Specific-fit exhaust muffler for select Chevrolet Impala and Chevrolet Monte Carlo models
• 100% stainless-steel body construction
• Oval combination muffler design
• 2.25-inch inlet and 2.5-inch outlet
• Offset inlet configuration with center outlet configuration
• Overall length: 29 inches
• Body dimensions: 15-inch length, 11-inch width, 5.5-inch height
• Pipe connection inlet and tip-style outlet

Detailed Description

Walker Quiet-Flow SS muffler 21399 is engineered for direct-fit exhaust service on 2000-2005 Chevrolet Impala and 2000-2005 Chevrolet Monte Carlo applications. The stainless-steel body helps resist corrosion in demanding underbody conditions, while the oval combination design supports OE-style exhaust tone and steady flow characteristics. With an offset 2.25-inch inlet and center 2.5-inch outlet, this muffler matches the routing used on the listed vehicles and supports a clean replacement for worn or damaged factory mufflers.

This part cross-references Gates 2310 for the same application. If you are replacing a factory muffler on a Chevrolet Impala or Chevrolet Monte Carlo, Part Number 21399 provides a fitment-specific option that aligns with the original exhaust layout.

What It Helps Address

• Exhaust noise from a worn or internally damaged muffler
• Corrosion-related muffler failure on stainless-steel replacement applications
• Restricted exhaust flow caused by deterioration inside the muffler
• Fitment issues when replacing the original muffler on 2000-2005 Chevrolet Impala and Monte Carlo models
• Factory exhaust tone changes after the original muffler has aged

Installation Notes and Tips

• Fits 2000-2005 Chevrolet Impala, N/A
• Fits 2000-2005 Chevrolet Monte Carlo, N/A
• Confirm inlet and outlet diameters before installation: 2.25-inch inlet and 2.5-inch outlet
• Verify offset inlet and center outlet orientation against the existing exhaust layout
• If the vehicle uses a welded assembly, replace all required exhaust components during service
• Check overall muffler length and body dimensions against available underbody clearance

Quality Assurance

Walker positions Quiet-Flow SS mufflers as stainless-steel replacement parts with precision fit and OE-style sound characteristics. Part Number 21399 is built for the listed Chevrolet Impala and Chevrolet Monte Carlo applications and is backed by the product line’s limited lifetime warranty coverage noted for these fitments.